Pneumatic time-switch.



G. H. PARSONS. PNEUMATIC TlME SWITCH.

APPLICATION FILED IAN. 16.1915.

' ,139,066. Patented May 11, 1915.

UNITED STA-'rus PATENT oFFIoE.

GEORG-E H. PARSONS, OF STAMFORDQCONNECTICUT, ASSIGNOR OF ONE-HALF TO T. ('JO`UCI:`I.' OF STANFORD, CONNECTICUT.

PNEUMATIG TIME-swrrcn.

Application led January 16, 1915. Y Serial No. 2,576.

To all whom t may concern' Be it known-that I, GEORGE I-I. PARSONS, a

subject of the King of Great Britain, re-

ated to close the circuit and which shall be provided with a bellowsfthe action of which is to delay the opening-of the circult for a predetermined time` l v after operation, my

novel switch being applicable to various uses in which it is desirable to have a manually operated switch remain in the circult closy ing position for a short time after the operator has removed his finger from the circuit closing element.

uses to which my novel switch is adapted, I will mention the lighting of an electric lamp in an unlighted hall or in a. room where it is required to locate andlight the gas or a lamp or to operate an electric socket switch, or for use in connection with a cigar lighting fixture, or with an automobile horn to prolong the sound.

With these and other objects in view I have devised the novel pneumatic time switch which I will now describe in connection with the accompanying drawing, in which I have illustrated the use of my novel switch in connection with an electric lamp, similar reference characters being used to indicate like parts in all of the views.

Figure l isa perspective view illustrating the use of my novel switch in connection with an electric lamp, the apparatus being in place on a wall; Fig. 2 a perspective view on an enlarged scale, the-case being broken away to show the interior structure; Fig. 3 a detail elevation showing the position of the bellows and the springvcontact in the which lies outside the case, t e base, 'indi-v cated by 12, being attached to a suitable bracket or frame 13 within the case.

Specification of Letters Patent.

Patented May 11, 1915.

14 denotes a bellows which is secured to the case and the valve 15 of which may be arranged within the bellows as in Fig. 4' or on the outer side thereof as in Fig. 5.

16 denotes a spring the action of which is to distend the bellows. In thelform illustrated in Fig. 4, the upper endf of the i sprin passes through a felt bushing in an eye 1 the shank of which passes through the hole 18 in the bellows and engages the valve. The action of the spring therefore in this form is to simultaneously hold the valve closed and distend the bellows, air slowly forcing its way underneath the valve and into the bellows. In the form illustrated in Fig. 5, atmospheric pressure holds the valve closed, a small hole 19 being provided through which air may slowly enter the bellows when in the collapsed condition.

The eye in this form engages a member of the bellows.

20 denotes a battery from which an electric connection 21 leads to the lamp and a connection 22 leads to a contact spring 23 attached to the bracket.

24 denotes an electrical connection leading from the lamp and secured to the .bracket in position to be engaged by contact spring 28.

25 denotes a stud or screw extending outward from the bellows in position to engage contact spring 23 see Fig. 3) when the bellows is distended and carry said spring out of engagement with electric connection 24, thus opening thecircuit.

26 denotes a push vpin normally retained in the retracted positionI by a spring 27. In

Fig. 4 I have shown the inner end of this push pin as bearing against bellows spring 16, its action being to first raise the valve by means of eye 17 and then to press the bellows tothe collapsed condition. In the form illustrated in Fig. 5, the inner end of the p ush pin may act leither against the bellows spring or against the bellows, in pressing the bellows to the collapsed condition, the valve opening as soon as pressure is applied. As a means for adjustably limiting the collapsing movement' of the bellows, I have shown a projection 28 on the bellows which is adapted to engage va., stop nut 29 on an adjusting screw 30, the

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move the stop nut or from the projection and thus determine to what extent the bellows shall be collapsed by operation ci the push pin.

'lhe operation is as follows :-The circuit is closed by the engagement of contact spring 23 with electrical connection 24. The normal position of the paies is with the bellows distended and the circuit broken owing to the tact that Contact spring 23 is held out of engagement with connection 2a by the stud extending from the bellows (see Fig. 3). @poration of the push pin causes the bellows valve to be raised and presses t the bellows to the collapsed condition. The

movement oi the stud backward from the position shown in Fig. 3 permits the spring contact to engage connection 24: and close the circuit. The push pin is returned to its normal or retracted position by the spring the instant the pressure is removed. The circuit remains closed, however, and the lamp lighted until dist-elution of the bellows causes stop 25 to torce the contact spring out otengagement with connection 2a'. The length ot" time required to distend the bellows and open the circuit is determined by adjustment of stop nut 29 which is engaged by the projection on the bellows. H the bellows is allowed to only partially collapse, the time required lfor the distending movement is shortened. Tlf the bellows is allowed to entirely collapse, the time required for distention is lengthened. As soon as the pressure upon the push pin is relieved, the bellows spring will act to distend the bellows. The distending action is relatively slow as in the :torni illustrated in Fig. d the must work its way under the valve slowly as the spring holds it in the closing position and prevents it from being appreciably raised by atmospheric prsure. In the form illustrated in Fig. 5, atmospheric presaisance sure holds the Valve closed and a small hole is providedin the bellows or the valve to permit air to enter slowly.

Having thus described my invention I claim l. A switch of the character described comprising an electric circuit, a bellows acting when distended to open the circuit, a spring controlled push pin adapted to collapse the bellows and close the circuit, a spring acting to distend the bellows and open the circuit, a projection on the bellows and an adjustable stop adapted to be engaged by said projection to limit the collapsing movement of the bellows and consequently the time required for distention.

2. An apparatus of the character de-A scribed comprising an electric circuit, a bellows having a valve and acting when distended to open the circuit, a spring acting to retain the bellows valve in the closing position and also to distend the bellows and means acting to open said valve, collapse the bellows and close the circuit.

3. An apparatus of the character described comprising an electric circuit, a bellows having a valve and acting whendistended to open the circuit, a spring acting to retain the bellows valve in the closing position and also to distend the bellows, a push pin acting to open said valve, collapse the bellows and close the circuit, and means for regulating the collapsing movement of the bellows and consequently the. time required for distenton and the opening of the circuit.

ln testimony whereof I aliix my signature in presence of two witnesses.

GEORGE H. PARSONS.

Witnesses:

ETHLL G. BENEDICT, J. J. MCDONNELL.

l'oples of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

' Washington, D. E. 

